Plasma discharge current from a plasma device such as Hall effect or similar type plasma device is known to be unstable and oscillatory. Because lifetime erosion is proportional to its power and the instantaneous power at the peak current is very high, the large magnitude of plasma discharge current oscillations are suspected to cause increased erosion and reduced the lifetime of the plasma device. Some evidence that plasma discharge current oscillations may reduce lifetime of a Hall plasma device is disclosed in Optical Boron Nitride Insulator Erosion Characterization of a 200W Xenon Hall Plasma device, by Hargus et al., AIAA-2005-3529, 41st Joint Propulsion Conference, July 2005, incorporated by reference herein. As disclosed therein, an increased boron nitride presence in the plasma was correlated with discharge oscillations.
One conventional method to minimize the magnitude of plasma discharge current oscillations is to manually adjust the amount of magnet current delivered to the plasma device. However, manually adjusting the magnet current is cumbersome and may not be performed when the plasma device is operational.